performance Junior

Explain caching strategies

Short Answer

Caching stores computed results to avoid repeated expensive operations. Strategies include read-through, write-through, cache-aside, and write-behind.

Detailed Answer

Caching strategies: 1. Cache-Aside (Lazy Loading): - Check cache first, if miss, query DB, store in cache - Most common in Laravel (Cache::remember) 2. Write-Through: - Write to cache and DB simultaneously - Ensures consistency but slower writes 3. Read-Through: - Cache automatically loads data on miss - Similar to cache-aside but handled by the cache layer 4. Write-Behind (Write-Back): - Write to cache immediately, DB asynchronously - Fast writes but risk of data loss Laravel Cache facade implements cache-aside: - Cache::get / Cache::put / Cache::remember - Tags for grouping related cache entries - Multiple drivers: file, Redis, Memcached, database

Code Example

Example

<?php
// Cache-Aside (most common)
$posts = Cache::remember('posts:published', 3600, function () {
    return Post::published()->with('user')->get();
});

// Tag-based caching (Redis/Memcached)
Cache::tags(['posts', 'home-page'])->put('featured', $posts, 3600);
Cache::tags(['posts'])->flush(); // Clear all post caches

// Cache invalidation patterns
// 1. Time-based: TTL expires automatically
Cache::put('key', $value, now()->addHour());

// 2. Event-based: Clear on data change
Post::created(fn () => Cache::forget('posts:all'));

// 3. Manual: Clear specific cache
Cache::forget('posts:all');

// Multi-level caching
function getDashboardData()
{
    return Cache::remember('dashboard', 3600, function () {
        // Expensive computation here
        return $this->computeDashboard();
    });
}

Explain caching strategies

Short Answer

Detailed Answer

Code Example

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